1. Field of the Invention
This invention is directed to a carton feeder assembly including supply assembly, selector, opener and erector apparatuses, a system including these apparatuses, and methods for supplying, selecting, opening, and erecting collapsed paperboard cartons and other substantially planar workpieces.
2. Description of the Related Art
Various packaging operations are designed to package goods, for example, consumer items such as beverage and food containers, into paperboard cartons for shipment. Such packaging operations are well known, and include some mechanism for supplying the empty cartons to a packaging area, where the containers are placed into the cartons. These prior devices typically include mechanisms for erecting the collapsed carton, and for placing the carton onto a conveyor.
A prior system known as an overhead rotary feeder is mounted above the conveyor of a container grouping apparatus. The overhead-type carton feeder includes a central drive shaft with a pair of opposing mounting plates attached to the shaft at its respective ends. Toward the periphery of the plates, four vacuum shafts are rotatably mounted each having tubes extending perpendicularly therefrom. The tubes include suction cups at their ends. As the drive shaft of the overhead feeder rotates in, for example, a clockwise direction, the vacuum shafts rotate in the counterclockwise direction so that a pair of suction cups for a shaft momentarily faces a folded or collapsed carton in an overhead magazine. The suction cups releasably attach to the face of the folded carton and rotate downwardly toward the conveyor so that centrifugal force and gravity cause the folded carton to open. As the vacuum shaft further rotates, the opened carton is placed between lugs on the conveyer, which complete erection of the carton and move the carton to the next process step of the packaging operation.
Although meritorious in many respects, the above-described system suffers from significant drawbacks. The carton magazine also must be located over the conveyor, thereby requiring the operator to climb above the conveyor to load the carton supply magazine. The overhead feeder also decreases the operator's visibility of other machine elements and processes. Also, the speed of operation of the above-described system is limited, especially for large cartons, because at relatively high speeds of operation the force of air against the carton can be large enough to overcome the suction applied by the suction cups. This results in the cartons being released before placement between lugs on the conveyer, causing interruption of the entire process. Further, other inefficiencies and drawbacks are associated with such an overhead carton feeder system, which must releasably hold the carton during the counter-rotating carton erection and placement step. Therefore, there is a need for a system that will overcome the disadvantages noted above.